text:
Are there any cockpit indications when an engine has separated from the aircraft?
On this answer, there is a comment that asks if there is an alerting alarm of some sort when an engine falls off an airplane.
Is there a direct alarm from the engines specifically saying "You lost an engine" to warn that an engine has fallen off from the aircraft?

Do you mean that question literally?  Would you accept, "No, there is no alert"?  If that is not an acceptable answer, why'd you ask the question?

You need to be careful when asking for evidence to disprove something.  I believe that there is a teapot orbiting Jupiter.  Please provide evidence that there is not.  I recommend re-wording your question along the lines of "do any aircraft have an engine-off alarm?"

Do you mean an alerting system to indicate that an engine has literally departed the aircraft—as you said, when an engine falls off an airplane—or do you mean an alerting system for an engine power failure?

In modern airliners, there are up to 853 independently triggered engine-off alarms, although oddly enough, they are never present on cargo versions.

This question is not duplicated. This one is asking if there is an alarm if the engine is lost, the previous discusses about what happens with the fuel lines. They are related, but not the same question.

All passenger and crew scream in unison!!

Beat me to It!  This actually happened more commonly when piston engines swung huge propellers.  A harmonic vibration caused by imbalance and/or bearing failure would literally tear the whole engine off.

This is the indicator that shows you when one engine falls off in a multi-engine aircraft:

If the right engine falls, off, the little ball will move left. If the left engine falls off, the little ball moves right.
If you only have one engine, or both engines fall off, you need to use a different indicator that looks like this:

if both engines fall off, this white pointer will start to move towards the "40", and you might hear an alarm, a voice shouting "stall, stall", or feel the stick shake.
if you have one engine and it falls off, the white pointer will move, but in an indeterminate direction.

A superior pilot using his superior skills would immediately apply corrective rudder to keep the ball in the middle and begin a descent to keep the airspeed at a minimum safe speed. :)

it only works on the ground, but there is a little button on the yoke that says "transmit". if you press that button and ask for "maintenance", you can request that they jettison the engine.

"Voluntarily Jettison an engine?"  What sci-fi world do you live on??

Additionally, if the engine falls off of a single engine aircraft, the event may well be indicated by an uncontrolled tumbling of the airframe about the new CG, possibly followed by airframe disintegration.

that's a good point @JonathanWalters. Maybe the white pointer will start to go up instead of down.

Yeah, hard to tell with that one; I don't want to be the test pilot.

I have updated the answer to reflect your comment

You didn't mention the sudden silence in a single engine aircraft.

@rdp "maintenance" has this nasty habit of putting another engine back on when you aren't looking though.

My airplane doesn't have either of those instruments....

There are a couple of design flaws in that first instrument that have been there since multi engine aircraft first flew.  The first is that if the engine blows itself to pieces, but stays on the airplane, the indicator still shows that it has fallen off.  The indication is the same!  The second is that in every aircraft I've ever flown, I've drilled a little hole in the glass to let that bubble of air out and it's stopped working. Surely modern technology can overcome these problems?

You'd better get a new airplane then. Otherwise how  will you know if the engines fall off?

@rbp Wouldn't the white pointer on this fancy-looking gadget also start moving (likely in the "down" direction, but that might depend on the mode of jettison) in case of engine jettison during flight? That might be an even better indication than the nice-looking color instrument you show, but of course there doesn't seem to be any "danger" zone indicated in the readings.

what is the name of the engine separation indicator ?

The B-737 has a checklist for engine separation, but no specific alarm for it.  The absence of all engine indications might be a hint, though.
I've never heard of any aircraft with such an alarm, but I don't know about all of them out there.

Presumably the loss of that engine's monitoring data would trigger an "alarm" of some kind (at the very least the master caution will be tripped, along with probably every fault that engine can show on the EICAS display)

I think any pressure sensor (for an aircraft that has one) would reside in the (now departed) engine, rather than upstream.  If anything, the fuel FLOW sensor, IF it's still attached to the aircraft, would show a fairly high rate of flow.  The checklist on my aircraft directs pulling the fire handle, which among other things closes the spar fuel shutoff valve, which does stop fuel from streaming out.

@voretaq7: Only the master caution?!  I would more expect an engine separation to trigger the master warning...

@Sean  The only "master warning" on the 737 is the fire warning, and an engine separation most likely wouldn't trigger that.  The separation itself isn't a Master Caution event, but things like the generator now being off-line (in more way that one!) would probably trigger the associated master caution alert.

aircraft work a bit different when it comes to alarms and advice. There is indeed an alarm and an indication of an engine failure. You would notice that the indicators of the respective engine, like Exhaust Gas Temperature (EGT), N1 Thrust and N2 Thrust will all drop. You will also get an EICARS warning (or several), that lead to the conclusion, that indeed an engine has failed. There is yet another indication if there is an engine fire. Along with an alarm the engine fire extinguisher handle will light up.
However, there is no indication as of whether the engine has just failed or flamed out or separated. At least not from an instrument point of view. A good pilot however will at least suspect that an engine separation has occurred. For example, if an engine is failing, its indicators are going down slowly. N1, N2, fuel flow, everything is going down slowly until it reaches zero. An engine separation will also lead to a fuel leak, since the fuel will spill out of the pylon. Maybe there also have been engine issues before, like overheating, that led to the failure. On the other hand, if an engine separates, all indicators will go to zero pretty much right way. As all sensors are gone. Usually a missing engine will also change flight behavior. Another way to find out would be the cabin crew or a passenger telling the flight crew. Of course this does only work with wing mounted engines. Aircraft like the Boeing 717, which have tail mounted engines make it impossible for anyone in the cockpit or cabin to notice a separation. In addition, it helps to know what happened before... maybe a sound of an explosion, touching something with the wing, etc. would also lead a pilot to think that an engine could have been separated.
So to summarize: There is an alarm for engine failure and engine fire but there is no alarm for an engine separation. It will just be an engine failure alert. However, there are indications and signs which a good pilot will recognize to at least suspect the separation.

On a DC9/MD80/MD90/MD95/B717, you can see the front of the engines from the rearmost cabin windows, so separation would be easily noticed by passengers and cabin crew.

Good point. Maybe.. I never been in one neither as pilot nor as passenger. Thanks for letting me know. Learned something new.

So, considering you began with "aircraft work a bit different when it comes to alarms and advice", is it a conscious design choice to not have such an alert? I could imagine that from a philosophy of instruments only relaying facts (as measured), allowing only the pilot(s) to draw conclusions from them, but I don't know whether that's a thing.


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How do runway declared distances affect my takeoff distance?
See these questions.
What is balanced field length?
What are runway declared distances?
My multi-engine jet airplane uses a balanced field length concept.  Most airports served by airliners have declared distances.
Obviously, my takeoff distance can't be longer than the runway length.  Does it have to be lower than all the declared distances?  TODA?  TORA?  ASDA?  LDA?

Actually, your takeoff distance CAN be longer than the runway if you use an overrun or a clearway.  Takeoff distance includes the distance required to climb to 35 feet above the ground in a jet.

@Lnafziger If you are using unbalance field length calculations, I would agree.  The question is about balance field length calculations.

Balanced field length calculations by definition are the greater of three factors.  As Lnafziger noted in his answer to the linked questions above these three factors are:

115% All engine takeoff distance
Accelerate-stop distance
Accelerate-go distance

The manufacturer will choose a $V_{1}$ speed that will all the accelerate-stop and accelerate-go distances to be as close as possible.  This reduced the takeoff distance to the lowest possible since the takeoff distance is the greater of those three factors.

This means that our takeoff distance must be less than certain declared distances.  See the linked questions for a discussion on declared distances.

The TORA value may or may not equal the runway length but it will never be greater than that length.
The TODA is the TORA plus a clearway.
The ASDA is the TORA plus a stopway (it can be lower than the TORA value).

Using common sense, our accelerate-go distance cannot be greater than the TODA value and our accelerate-stop distance cannot be greater than the ASDA value.
If we take this one step further, since we have one number for takeoff and we don't know if that number is limited by the accelerate-stop or accelerate-go performance we cannot use the TODA value for the accelerate-go distance.  We must use the TORA value.
Hence, for multi-engine airplanes with balanced field length calculations we are limited to the lower of the TORA or ASDA values for our takeoff distance.

As Aeroalias and Lnafziger pointed out, for unbalanced field length calculations we can indeed use the TODA value for the accelerate-go distance and the ASDA value for the accelerate-stop distance.

References:
The NBAA has some great videos on the subject.  Here is the video on YouTube.
AOPA also has information on the subject

Actually, the take off distance given in runways will be greater than the runway distance as it will include the distance to overcome a predetermined obstacle.

Source: tc.gc.ca
The balanced field length is dependent on the aircraft configuration among other things and is usually available in AFM. The airfield lengths, on the other hand are made available so that operators can decide which aircraft to operate based on the runway lengths available.
In general, the ASDA should give you the available distance for taking off as it gives the required field length available in case you decide to abort the takeoff for whatever the reasons.

An explanation of each of the terms in the graphic would probably help the people that don't already understand this a lot.

@aeroalias I would agree that the takeoff distance can be greater than the runway for unbalanced field length calculations.  If that is the case which declared distance must you be lower than?

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Why does a jet engine acquire a metallic whine when in full power?
I had a flight yesterday on an AA Embraer ERJ-190. As the plane idled at the end of the runway there was the familiar high-pitched jet whistle, which increased in pitch as the engine started spinning up. But, when it reached full power, the whistle was joined by a far-lower-pitched metallic whine, which persisted until the pilot throttled down after the initial steep climb.
I've heard this before on some (but not all?) planes. By ear, the whistle was about four an a half octaves above the whine, which is about a factor of 24 (I may have been off by an octave, or another factor of two).
On a past flight I calculated that if the main fan spun so that its outer edge was moving at the speed of sound, the whine would be at about the rotational frequency of the fan. If the fan had 24 blades (or 48 if I have the wrong octave) then the whistle could be the fan blades, and the whine the fan itself.
One explanation could be that there's something asymmetrical about the fan, e.g. one blade is a bit too long and hits the housing when at full power. (Of course, this would make no sense from an engineering and reliability standpoint.)
What causes that far-lower-pitched metallic whine?
Edit: I just returned on a JetBlue flight, but also using an ERJ-190. Where before I was seated in row three, this time I was in row 24 of 25. On takeoff, there was only a loud roar; no "whine" or "whistle". So, it's pretty clear that the noises I'm referring to above are emitted from the engine intake.
And, on this page I found a photo of the ERJ-190's GE CF34-10E Efficient Engine's inlet:

Sure enough, the intake fan has 24 blades. So, my above guess on the frequency ratio between my "whine" and "whistle" has some physical basis.
And, I'd like to respond to a comment by @kevin:

Could it be that the "whine" always exists in the frequency spectrum, but it's just below our human ear detection threshold (both pitch and amplitude) during low rpm operation?

When the "whine" starts and ends, my impression is that yes, the pitch rises as it initially strengthens, and falls as it finally fails. However, its volume is strongly pitch-dependent, so that it is far quieter when running at 80% of the maximum pitch/RPM, and inaudible below that. It sounds as if that blade which purportedly hits the housing only does so above a certain RPM (again: this is what it sounds like, it almost certainly is not what is actually happening). More generally, my interpretation is that the cause of the "whine" only happens above a certain RPM.
Edit 2: @fooot was kind enough to point out another question that is basically a duplicate. My text and suppositions are (I think) a lot clearer, but the other question links to two videos that demonstrate exactly what I've been talking about:

Airbus A320 with IAE V2500 engine
Airbus A320 with CFM56 engine

Neither of the answers to the other question are correct; one focuses on the fan blade noise (too high-pitched) and the other on pressure equalization vents (not engine-speed related).

Could it be that the "whine" always exists in the frequency spectrum, but it's just below our human ear detection threshold (both pitch and amplitude) during low rpm operation?

It's most likely the tips of the blades locally exceeding the speed of sound.

"24 or 48" could be a matter of harmonics. The first harmonic is at double the ground frequency, i.e. exactly one octave higher. (And yes, a factor of 24 is 4.58 octaves)

The number of blades matches the ratio between the two tones I hear, which strongly implies that one tone is at the per-blade frequency, and the other tone is at the per-rotation frequency.

Interference between static guide vanes ("turbine blades" is a misnomer, these are blades that that don't turn, they are in the compressor section) and the compressor vanes would be be my guess. Like the interaction between a helicopter main rotor and tail rotor, making the "chopper" sound. I'm just a layman, though...

I found the following RPM limits for the GE CF34-10E: 6325 RPM and 18018 RPM for N1 and N2 stages. At 100% power, the RPM for the N2 stage is 17160 RPM.
So basically we're looking at a rotational frequency of about 300 Hz. Well above the 20 Hz threshold for hearing, even if not at 100% power.
Where things get interesting is the fact that the human ear becomes markedly less sensitive to sounds below 300 Hz. So when the engine spins up from 200 Hz to 300 Hz, not only will the increased power probably produce more raw noise, it's also at a frequency that's more audible. But exactly how strong that effect is, is hard to describe. There's even a standard for this, specifically aimed at airplane noises!

My big question is why a turbine, which is undoubtedly precisely balanced and symmetrical, makes a strong sound at its fundamental rotation frequency.

The turbine has to interact with the air, that's the whole point of a turbine. The rotational motion is periodic. Balancing will reduce asymmetries, but you cannot realistically eliminate them. But even if you did, the input airflow isn't perfectly symmetric either. A small disturbance will likely cause a vibration which dampens only slowly - it's hard to dampen vibrations in fast-moving machinery.

Not sure what do you mean by "metallic", but the sound of the Embraer ERJ-190 engines is quite different from the sound of larger engines, like those of A-320s or B737s...  I guess the fan does produce a much lower frequency sound due to much lower rotational speed.  And at full throttle, the 190's engines really do sound "different" compared to lower power settings.  I've even noticed some sort of buzzing cyclic variations, both in sound and some slight vibration too.  Let's not forget the Embraers are lighter in overall weight and construction, and their feel is indeed different.  Anyway, any prolonged contact between rotor and stator is not desirable or common.  There is a "seal" of the labyrinth type, but it is non-contacting.

It's possible that you are hearing the blade tips 'brushing' on the honeycomb seals (it's what the blades seal into at the tip). Look up "Turbine shroud seals...."

Can you provide more detail? Although there can certainly be contact there, it seems like this would cause wear issues if the blades are regularly rubbing on the seals.

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Why is there no alarm when the transponder is turned off?
When the transponder on Malaysia Airlines Flight 370 went off, there was no ALARM. The satellite kept getting pings, and apparently "knew" that the transponder was off. Would it not be a great idea if the Malaysia Airlines got an alarm indication that the transponder was off on one of their planes? The airline could have radioed the pilot and asked what the trouble was. If the pilots did not respond, some jets could have been scrambled to checkout what is going on. The scrambled jets could have followed the airliner for hours and watched them crash in the ocean, when they ran out of fuel. We would know EXACTLY where the airline crashed!

Is the premise that "the satellite apparently knew that the transponder was off" even true? How would it know that?

You are looking at this thing from the hindsight. It's clear what we would need to do when we already know what comes next, but normally we don't know what will happen, and therefore cannot cover every situation.

Attach a rope to each flight, so when it gets lost, just pull the rope

Because it's not worth it.
Quick, name me another accident where a transponder-off alarm would have been exactly what was necessary to save the crew, the passengers, or the airframe?
Hint: there aren't many.
The number of false positives would drastically outweigh the number of actual events where a transponder alarm would have been able to do some good.  For example, air traffic control might ask an aircraft to turn off their transponder.  Nothing dangerous there, but alarms would be going off back at dispatch.  Good idea on paper, but not practical enough to make it worthwhile in the real world.

There's also no reason to believe such an alarm would have "saved the crew, the passengers, or the airframe" in this situation either - If the aircraft descended to an altitude below radar coverage the operational status of the transponder becomes irrelevant. On the other hand raising an alarm would give the flight crew another problem to deal with if they need to deactivate the transponder in response to an emergency (say it's shorting out and in danger of starting a fire). As you said, the risks simply outweigh the benefits here.

Quick, name me another accident where a transponder-off alarm would have been exactly what was necessary to save the crew, the passengers, or the airframe?
GOL 1907, where the Embraer pilots inadvertently set transponder to stand-by while the captain (I think) pressed the relevant LSK with his foot(!) while using the foot rest. Also let's not forget that TCAS requires transponder to function.

Yes, GOL1907. It is probably the only one and it would have helped the most if the ATC radar bitched more loudly about loosing the secondary target instead of just showing the primary data with single symbol change.

@Jan Hudec True and that's the theory of Swiss cheese holes and that one factor by itself is not enough to cause an accident and bla bla bla. The point is to patch as many holes as possibles, and (regarding GOL) both transponder and the RADAR UI are safety holes that should be closed. Always IMHO.

@SteliosAdamantidis - Yep, GOL1907 is the only one I could think of as well.

The airline could have radioed the pilot and asked what the trouble was.

The airline doesn't generally have a direct line of contact with their aircraft. That's the job of air traffic control. It might be possible for the airline to ring up ATC and see whether they can contact the aircraft, but if ACARS is turned off then the only viable option is HF radio which doesn't always work. Some aircraft have a satellite phone in the cockpit, no indication whether MH370 did.
Anyway, it was the middle of the night. Might be tricky to get somebody at ATC to answer the phone.

If the pilots did not respond, some jets could have been scrambled

By whom? Who is paying for that? If jets were scrambled every time an aircraft couldn't be reached over the ocean, there would be a lot of false alarms.

to checkout what is going on.

So, you've got jets in the air, now where's the aircraft? Remember, it was nighttime and the aircraft wasn't on radar anyway. If they had turned off the lights, there would be no possible way to find the plane. By the time the jets get to where the flight was last estimated to be, they could have gone in any direction.

The scrambled jets could have followed the airliner for hours

What's the range of your jets? Remember they would probably like to get back home too, so cut that in half. Where are they going? Whose airspace? If these are military jets, who clears them to fly into another country's airspace? Would Indonesia mind being overflown by Malaysian fighter jets on short notice in the middle of the night?

"The airline doesn't generally have a direct line of contact with their aircraft." Can one of the airline pilots here confirm if this is true? I was under the impression that it was normal for airliners to have the ability to talk to the airline dispatch.

"Remember, it was nighttime and the aircraft wasn't on radar anyway." My understanding of news reports was that it was tracked on both Malaysian and Thai military radar for quite some time after they turned off the transponder, including the entire time that it was crossing the Malay Peninsula and out into the Straights of Malacca.

some jets could have been scrambled

By whom? Who is paying for that?
By the air force of the country that is being over flown by an unidentified aircraft, also unreachable by radio, that's who. I'm surprised that neither Thailand nor Malaysian Air force scrambled some jets. I would think this would be a routine procedure in this type of situation. This could have been another 9/11 type of incident, thankfully, it wasn't. Isn't that what an air force is for?

Granted, it would have been a huge logistical task, particularly on short notice, to follow the airliner until it crashed. Probably involving air to air refueling and the coordination of several nations.
Who's paying for the HUGE ongoing search for the downed aircraft? The real-time scramble would no doubt be cheaper. There is a slim possibility some survivors could have been rescued. Virtually no chance of that now.

Again, you're looking at this with the benefit of hindsight. "If only they had done X at time Y, this could have been avoided." Sure, but while it's actually happening it is very difficult to determine the correct course of action. Even for several days afterwards, searchers were looking in a different ocean. At the time, nobody knew that the blob on military radar displays might have been MH370.

On the blog: How do you do line breaks? Two SPACES does NOT work! I tried!  Why am I limed to several hundred characters? Others have left comments with MANY more than I could!

@Gilligan, I have no idea what you're referring to when you say "On the blog" but if you're looking for help with this site, I would recommend taking a look or searching through the Help Center and if you can't find your answer there, ask someone in The Hangar (our chat room).

Turning off the transponder, radio, flight recorder, engine, air conditioning, lavatory or any of the other things on the Minimum Equipment List does not usually qualify as an emergency. There are spares which can be switched on as soon as deemed prudent. If the pilots have something to say, they will. If they can't, they probably have more important things to do. Aviate, Navigate, Communicate. In that order.

then bump up the transponder from the minimum equipment list

To where? The transponder is already on the MEL. Commercial flights cannot depart without everything on that list installed and working. (hence: "Minimum"). No rules against things breaking mid-flight. Private aircraft don't always need one, and no aircraft needs one if they are not flying through controlled airspace. In that situation, no one would be listening to the transponder anyway.

@paul My understanding is that that's the exact opposite of a Minimum Equipment List: the MEL is precisely those things which can be inoperative (possibly with some modified procedures). On that note, I find it hard to believe that an engine failure doesn't constitute an emergency dictating a landing at the nearest airport that can take the plane.

Why is there no alarm when the transponder is turned off?

Because airlines trust their pilots and have systems in place to ensure their pilots are trustworthy. It is probably right to concentrate on preventing untrustworthy persons entering the cockpit before worrying about real-time remote monitoring of the actions of untrustworthy persons in the cockpit.

The satellite kept getting pings, and apparently "knew" that the transponder was off.

This is not correct. The ACARS system and the transponder are separate systems. The satellite in orbit "knows" nothing, it's just a relay. The satellite's base station receives the data and forwards it to customers whilst monitoring the satellite service/performance. As I understand it, the base station equipment is not expected to peek into their customer's data content and make judgements about it's meaning.
ACARS uses VHF over land and only uses satellite communications (SATCOM) when out of VHF range. So the satellite systems not receiving data is not unusual and should not trigger an alarm.
The Inmarsat satellite ground station could not inferred that ACARS had been turned off inappropriately. This is because it doesn't know if the aircraft has landed and systems turned off normally. The Inmarsat company probably don't know every time an aircraft deviates from schedule, e.g. to divert back at the airport to check a fault light. The Inmarsat base station also didn't know the location of the aircraft other than it was somewhere on that side of the planet. The hourly handshake is conducted using the broad regional beam, not one of the narrower beams.
It is fortunate that Inmarsat keep logs and that the logging system chooses to keep certain data such as signal strength and frequency rather than discarding it. This enabled Inmarsat's engineers to analyse those logs days and weeks after the events. But this analysis is not routine and real-time (and it would probably be a very inappropritae solution to make it so).
Malaysian Airlines had not subscribed to the more continuous† data reporting systems available through ACARS (and Inmarsat). So the absence of ACARS or other transmission is even more unremarkable from Inmarsat's perspective at the time.
In the normal course of things it is not the job of Inmarsat to interpret the data being transmitted  to it's customers (the airline, plane maker, engine maker etc). It's job is to relay data to it's customers and those customers can then use that data as they need.
Since those customers had not subscribed for continuous† transmission, no-one could know what  was happening in the cockpit.
Even if the continuous† transmission was subscribed to, there is no guarantee that the state of the transponder would be part of that data, nor that there would be a monitoring system at the airline capable of issuing alerts for unusual settings of the transponder.
ACARS itself is just a reporting system. I believe the content of the data reported is selected by the airline.

Notes:
† By continuous I mean the sort of monitoring used for AF447. As I understand it, this isn't completely continuous, just more frequent reporting and as-needed throughout the flight to report certain events as they arise.

The question presumes capabilities that don't exist (the ACARS satellite link doesn't "know" about the radar transponder), presumes the transponder was intentionally turned off (likely, but very speculative, we have no evidence), and presumes the airline monitors planes in flight (they do not), while ignoring the fact that Malaysian military radar operators had the transponder-less blip on their display(s), had radios, and were part of the military that would have sent fighters to investigate.
Because their range is finite and limited, air traffic radar will "lose" transponder signals when a plane flys out of view. Signals stopping is a constant occurrence. If I follow the timeline correctly, the copilot spoke to air traffic control after the transponder signal stopped. Air teaffic control are supposed to monitor the planes they are watching. Why didn't they ask the copilot what was up? When the transponder signal stopped, was the plane at a distance and altitude where  disappearing would be expected. ?

Soon after ATC noticed that the transponder was off, they tried to raise MH370 on the radio. Failing to contact them, they asked other flights to try to contact the plane.

So, someone DID try to contact the flight! I hadn't heard this on the news. And what was ATC's followup? Seemingly nothing, just wait to see if they arrive at the destination? Is there a normal procedure for this type of situation?

If pilots are alive and conscious they will generally be sufficiently aware by other clues. Given that ADS-C which MH370 was using is contracted to ATS without a transponder the feedback from ATS would cease.
There are only so many alarms you can bombard a pilot with before it becomes a counter-productive distraction in an emergency.
It is just a presumption that MH370's transponder was turned off since the Flight Aware website notes that MH370's transponder did briefly send signals again about three hours after take-off at 03:48-03:51 MYT.
Because these transponder returns were prompted by MH370 flying through civil radar coverage and being painted by civilian PSR radar then it may be that it flew through a gap in radar coverage and MH370's transponder was not switched off at all.

the Flight Aware website notes; any link to substantiate your claims?


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With radio not working, why it is more important to stay away from exactly class D airspace?
The instructions how to land when the radio is no longer working state as the first item "stay away from the class D airspace".
Why is the class D specifically mentioned in these instructions? How it could be that A, B which "has the most stringent rules" and C are less a problem?

The procedure in the linked answer assumes you're VFR. If you're in class A airspace, that means you must be IFR, and there are specific (and somewhat different) procedures for IFR flights that lose radio communications--which may include landing at a class A/B/C airport. VFR pilots without radios should stick to class D/E/G airports, which are a lot more plentiful anyway. Most B/C airports are ringed by D/E/G airports, so unless you lose your radios while already inside class B/C airspace, those wouldn't be very logical options anyway.

This answer confuses me.  "VFR pilots without radios should stick to class D/E airports, which are a lot more plentiful anyway"  -- why not a Class G airport?  And why lump Class E in with Class D -- you don't need to talk to anyone to land at surface-level Class E, unless the weather is bad enough that you want to request SVFR.  Wouldn't it be more logical to say "VFR pilots without radios should stick to class G/E airports, which are a lot more plentiful anyway"?

@quietflyer I’ve updated to say D/E/G.  Personally, I’d rather use a D airport because there will be someone watching me land and, if there’s something more wrong than just lost comms (maybe I lost comms because I’m on fire!), call fire/rescue immediately.

I think you are mis-interpreting the answer, you should remain outside Class-D until the flow of traffic can be acertained. If you lose comms outside of a Class-B or Class-C, you should not enter that airspace, instead divert to a Class-D or E airport if possible. If you are already inside the B/C airspace, continue, but don't enter. Class-A is different, as it is not surrounding airports and you can fly IFR after you've gotten your clearance with lost comms.
The original question links to the AIM, Chapter 4, Section 2-13, read that and see if it clears things up.

FYI, Europe has a few airports in surface class A airspace, and some low-ish airways are class A too. Lots of different models outside the US on how/where to use the various classes.

@StephenSprunk While true, the answer which was linked to in the original questions is about US/FAA procedures.

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text:
Do crew need visas when landing at airports in countries other than their own?
If the crew never leave the plane, have they really entered the foreign country? What about if the crew leaves the plane, but not the airport? How do crews of international flights keep up with all of the visas they may need?

crew is only allowed 8 hours of flight a day with mandatory rest (to avoid fatigue), and often international crew will only fly a fixed route

@ratchetfreak max hours are different for long-haul 3- and 4-pilot operations.  Also those pilots will likely only fly one leg on a given day, but may fly to a different city on every trip.  Unless you are quite senior or your airplane only flies to very few cities, you probably won't end up with a line consisting of the same trip all month.

It all depends on the laws of the country that the crew is visiting.  Some do and some don't.  Many do unless they have a reciprocal agreement with the pilot's country, in which case they don't.
This would be a great question for a specific country pair, or even if you want to know the laws about a specific country (in which case we could give the actual requirements), but the best answer for a general question like this is "it depends".
In some cases, the crew isn't even required to clear customs unless they are leaving airport property.  Other times they have to clear as soon as they land.
Part of qualifying for a route with the airlines is making sure that you have the required visas.  Having two passports help a lot in getting multiple visas, because they can keep flying internationally while the visa application is in process.

Do you mean two passports from the same country? It's this legal? Every time I renew my passport, the old one gets stamped void. Do you mean dual nationality?

@RoboKaren It's often possible to have two valid passports from the same country. One reason is to allow you to travel to two countries that each refuse entry to people who have stamps from the other.

@RoboKaren If you can demonstrate the need (i.e. you need to send your passport out in order to get a visa and also need to continue flying in the meantime) then you can get a second visa in the US which is good for two years.

Addressing the "If the crew never leave the plane, have they really entered the foreign country?" question only -- yes.
I've done numerous turns to Canada, Mexico and the Bahamas where we just drop off passengers, pick up the next load and fly back to the US (specifically IAH or EWR in my case).  When you get back to the US, you will go through customs unless the station you did the turn at is a pre-clearance station (e.g. passengers go through US customs before boarding).  There are no pre-clearance stations in Mexico that I know of, but Canada has many and there are also a few in Europe.   My experience is all in scheduled part-121 operations, and this may vary for other operations.
If you get off the plane during the turn (aside from pre-flight duties) then you get to go through the local customs, immigration and security screening to get back on your plane.  This was quite painful in airports like Montreal where the walk to customs and back to the plane can be quite long.

authors: ajt.ru отзывы


text:
How can I get flight destination from ADS-B?
If I have aircraft details such as the callsign, transponder code, and ads-b info, how can I look up the departure and arrival airdrome? Is there an API to obtain this information in a programmatic way? How does flightradar24, for example, obtain this data?

some flights don't have destination data in flightradar so I suspect they query the flight plan of the owner of the flight

If you have the call sign, or Air Carrier flight number, you can track flights with http://flightaware.com. Air Carriers are required to file IFR flight plans so the destination is in the system and trackable. Part 91 (general aviation) and Part 135 (non-scheduled for hire) IFR flights also file a flight plan and their origin and destination are trackable. Most Part 135 flights are on an IFR flight plan but most Part 91 flights are not. However, Operators can block the release of information so FlightAware may not have the info for some aircraft. The information is also available if Part 91 fliers are receiving flight following. If a Part 91 operator is not in contact with ATC the information will not appear in FlightAware.
FlightAware gets the info from the FAA, so there must be an API for it but I don’t know anything about it. “Flightradar24 has a network of more than 3,000 ADS-B receivers around the world that receives plane and flight information from aircraft with ADS-B transponders and sends this information to our servers.” It also gets data directly from the FAA radar with a 5 minute delay.

Yes receivers get info streamed/sent by aircraft like CallSign, Squawk, Altitude, Track, ....
But i need pair this info with data (Airdrome ICAO FROM, Airdrome ICAO TO) and i do not know how to get this infos.
I think I have Call sign -> I call webservice XYZ id this web service send me response with data (ICAO FROM , ICAO TO) or similar data.
:)

Probably a bit late to post an answer to that question, but I'll throw in my two cents.
Not sure where flightradar24 gets its data from. I just know that these guys at ADSBExchange provide unfiltered un-encrypted flight-data through their API (click this link https://public-api.adsbexchange.com/VirtualRadar/AircraftList.json for a complete list of all aircrafts tracked by ADS-B receivers world wide - in json format)
You can easily filter the above url, depending on which area you're looking at. For instance:

all aircraft between 0 and 100 km of the lat/long of Phoenix Sky Harbor Airport, use: http://public-api.adsbexchange.com/VirtualRadar/AircraftList.json?lat=33.433638&lng=-112.008113&fDstL=0&fDstU=100"

(take a look at the API documentation for more details)
Once you've filtered around your area of interest, you can easily look up departure and arrival aerodromes by filtering the json file. For each aircraft in "acList", look for the fields "From" and "To" for the departure/arrival aerodromes respectively.
It's quite straightforward to parse Json. Lots of languages these days allow you to easily do that with ready made libraries (take a look at this thread for parsing json with Python)
Hope this will be useful to someone :)


text:
Why should you not turn in the direction of an inoperative engine?
In two-engine aircraft with wing-mounted engines when one engine quits the aircraft will have a natural tendency to turn to the dead engine. So if you need to turn, it seems logical it should be easier to turn that way.
However in the discussion here is a comment:

By dinger on Monday, Aug 11th 2014 13:42Z:
  SOP in a twin is NOT to turn in the direction of the failed engine. Right engine failed and they turned Right.

Is it really standard procedure, and if it is, what is the reason behind it?

Example of an accident where the turn to the dead engine side was determined as one of the fatal factors http://en.wikipedia.org/wiki/%C4%8CSA_Flight_001

@VladimirF: I don't see that say they tried to turn anywhere, only that the aircraft banked because of the asymmetric thrust.

The investigators published the causes as follows: Failure to bank the plane towards the working engines side "Příčina nehody:... nenaklonění letadla na stranu pracujících motorů... "

@VladimirF: Yes. But that means they failed to properly counter the torque, not that they tried to execute turn and did it wrongly.

No place to discuss it here, but they actually tried to circle to land and that lead to the fall. It is necessary to look into the full report or the book http://www.databazeknih.cz/knihy/nehody-dopravnich-letadel-v-ceskoslovensku-3-dil-79104

The best place to look to see if this is actually required is in the POH / FOM for the specific airplane.  I'd be surprised if the engine out procedures say that you are not allowed to turn into the dead engine though, but rather that you are required to keep a specific minimum airspeed so that it isn't an issue.

As a side note, many pilots don't understand the reason for leaving the slip-skid ball offset slightly (typically about 1/2 ball width) toward the good engine, as opposed to applying enough rudder to fully center the ball.  The reason has to do with the way the ball is affected by the sideforce created by the rudder itself.  If you apply enough rudder to fully center the ball, you are guaranteed to actually be flying slightly sideways through the air, which is not optimum in terms of staying aloft.

The AvHerald comment is correct, you generally do not want to turn towards the dead engine. The aircraft will tend to turn (both yaw and bank) towards the dead engine due to asymmetric thrust, allowing it to do so at low speed will make it difficult to end the turn, possibly to the point where you lose control. If you turn away from the dead engine, you'll have a tougher time getting into the turn, but the live engine will help you get out of it. That said, attempting low altitude turns with an engine out seems like a bad idea, you should concentrate on going straight and maintaining optimum airspeed to make sure you get some altitude
There are a couple of mnemonics when dealing with engine failures, like "dead foot, dead engine" (determining which engine failed) and "raise the dead" (keep bank towards the live engine)
I can only speculate as to why they chose to go right, either they wanted to avoid the populated area, or they were already unable to control the turn. The high density altitude would certainly affect the OEI performance as well, perhaps luring them into losing airspeed below Vmc.
Disclaimer: I'm not multi engine rated, and have no first hand experience. This is just what I've read.

This looks about right!

FWIW, when I went through multi-engine training in the early 1970s, the common wisdom was to avoid turning into the dead engine, and that is what I taught as a multi-engine instructor.

flying 4 engined turboprops we were trained to prefer turning away from the dead engine. The aerodynamic issues are the same. I've shut down lots of engines and 1-engine out was not a significant control issue. I would not go to extremes to avoid turning into the dead engine, but I certainly made a conscious effort of smooth, shallow turns and perfect rudder control. An outboard dead engine got more attention. Gross Ham-fisted control input has caused completely avoidable crashes.

I recall that the Senica, 2 engines, was a dog on one engine and turning into the dead engine was truly dangerous. It was on the knife edge where the good engine at full power might not keep above stall speed given a turn into the dead with the bit more lift loss, bit more drag from rudder cross control, etc. compared to "raising the dead."

Isn't this why Vmca should be observed, and not just stop turning one direction?

@lnafziger indeed it is, but it never hurts to take extra precautions in a high stress situation. With enough airspeed you can do aerobatics with shut down engines. But that's when things go according to plan, isn't it?

@falstro As a former engineer and professional pilot, I am VERY much a "fly by the book" kind of person.  The procedures are there for a reason.  Want to live?  Don't get too slow!  :-)

@lnafziger Im not arguing you should go below Vmca. I'm saying that I think even above Vmca you will have fewer distractions if turning away from the dead engine. Fewer distractions means less chance of accidentally letting the speed drop.

@falstro I know, and I'm just saying that if you don't go below Vmca then you don't have to worry about which way that you turn.  In this situation, it would be a cardinal (even deadly) sin to let the speed drop, so you cannot let yourself get distracted to that point.  Period!  For me it is such a high priority that I can't even see it happening!

I was recently PIC of a twin Aztec,  when I was on a single pilot IFR departure. At about 800 feet at gross weight, without warning there was a loud bang and the right engine quit.
I was able to make a wide left 270 tear drop turn into the good engine which was operating at full power.
My multi-engine training taught me the skills necessary to survive this failure. A turn in to the good engine is taught for a reason. Raise the dead...
This helps the rudder have the authority to over power the asymmetrical thrust of the good engine. I believe a turn into the dead engine may have resulted in loss of control, and death.
The main thing is DON'T PANIC... Fly the airplane...
The good Lord was in control as The aircraft was loaded at gross weight (5 passengers and baggage).
I was able to complete the turn and land safely opposite the direction of my departure.
The stall horn was chirping through out the shallow turn, but my airspeed was right at Vyse (blue line). We were NOT climbing. The cause of the failure has not yet been diagnosed.

Welcome to [aviation.SE]! This site is designed as a question-and-answer exchange, not a forum, and this is not really an answer to the question. Please take a look at http://aviation.stackexchange.com/help/how-to-answer for some tips on what's expected in an answer.

I think that was a great story.

All that training, and it was the good lord that saved the day. Amazing, but bit of a waste of money on flying lessons.

You should check out the recent videos on YT of new training by Dan Gryder and realize that if your stall warning was chirping you were much closer to a stall than you realized as stated by your description. The Blue line (Vmca) is for straight ahead flight only.

A spin is an aerodynamic, stable maneuver where one wing stalls and the other continues flying. To practice this maneuver once, turn into the dead engine of a twin engine airplane, the spin will be textbook perfect and you'll be back on the ground very quickly.

lol, 'practice this maneuver once'

But why does turning into the dead engine provoke spin more easily than turning into the live one?

The reason is that Vmca is not a fixed value (despite the red line), and actually increases as you are banked more toward the inoperative engine.  If you start from a position banked to the good engine, you will have more rudder authority if turning to the good engine.
This video does a good job of explaining this, and especially between 10-16 min shows why you want to maintain bank toward the good engine and it's effect on rudder use.

Remember that the red line speed is based on a very specific set of conditions.

@quietflyer, I believe he did—the Vmc is marked by a red line on the airspeed indicator in small twins.

@JanHudec -- absolutely, correct.

That’s kind of an old wives tale.  The truth is you can turn into the dead engine, if you do it right.
Most certified twins are pretty well behaved airplanes with a failed engine, except at low speeds and low altitudes.  Since control authority is more diminished here, there is s much greater tendency of the roll and yaw moments from the asymmetric thrust loading on the airplane to cause a departure from controlled flight.  You must be very careful when handling these airplanes in this regieme of flight and never attempt to apply power below the minimum control airspeed with a failed engine as this is a death sentence in a twin.  That being said smooth easy maneuvering of a twin at or above minimum safe single engine speed will be just fine, regardless of whether you are turning into the dead engine or not.
One key to performing the turn correctly is to keep the turn coordinated with the ball moved approximately 1/2 out of the center marks - “uncage the ball” - in the direction of the good engine.  This will ensure no sideslip in the turn.
As part of a multi engine checkride, examiners will fail the critical engine in a left hand traffic pattern, forcing the pilot to turn into the dead engine in order to return and land.  Examiners will also test things like engine failures in steep turns for MEI checkrides as well.

"except at low speeds and altitudes" -- nope.   Outside of ground effect, the aircraft does not care how close the ground is.

Try that with an inoperative engine at or below Vmc and see how well that works out for you.

At low altitude eg on climb out, airspeed is low, no accelerated airspeed from prop on side of dead engine, if you turn into dead engine, airspeed over that wing drops even more and it will readily stall hence spin!
With ample speed and altitude there should be no problem with a gentle turn.

@Federico, I think the answer, as it stands, does add a lot. It explains the Caroline's non-answer.

This answer is based largely on a critique of this video:

The video is interesting but I think it contained some fundamental errors in theory if not result.  From 8:54-9:12 the author is speaking as if sideslip is a result of side force. That's essentially an Aristotelian concept rather than a Newtonian one. Sideslip is not a result of sideforce-- turning is.  Rather, sideslip is a result of not being pointed the same direction you are actually going. Therefore it's inaccurate to say that when you are banked, the weight vector has a component that causes sideslip in one direction, or opposes sideslip in the other direction.
(Btw this pertains to related discussion in the answer
Could a plane be constructed to be fly in fixed-stick roll-stable circles? -- specifically the comment "From the point of view of the aircraft, lift is still acting in the plane of symmetry, but gravity does not and will cause it to sideslip.")
What's really going on in the twin-engine case is that the slip-skid ball reacts to all aerodynamic sideforce components (but NOT to the sideforce component contributed by gravity, because gravity accelerates the aircraft and ball together-- this can also be explained in another way involving "centrifugal force".)  When one engine fails on a twin-engine aircraft, if you want to exactly center an imaginary yaw string at the nose for maximum streamlining, the ball cannot be fully centered, because the rudder is strongly deflected and creating some sideforce toward the dead engine. That's why you leave the ball deflected about half a width toward the good engine--because it streamlines the fuselage.  And fundamentally the rudder, not the bank anlge, is the control what controls the position of the slip-skid ball.
The purpose of the banking toward the good engine is to stop the turn that would otherwise result (due to the rudder sideforce) when the ball is in the optimum position, NOT to influence the amount of sideslip that is present. Similarly it is incorrect to suggest the banking TOO FAR toward the good engine would slip the plane sideways through the air toward the GOOD engine and possibly stall the vertical tail as a result, as the author suggests from 9:25 through 9:28.
Now, granted, if we are simply using the ailerons as needed to establish and maintain a set bank angle, and using the rudder as needed to hold heading while flying at that bank angle, then FUNCTIONALLY things would end up working much as the author says.  (Except that the possibility of stalling the tail due to "too much bank" seems far-fetched-- are we really contending that the pilot is applying so much rudder toward the good engine that a yaw string would be deflected extremely far toward the good engine, despite the thrust imbalance?  I don't think this is the true purpose of the 5-degree bank limit cited in the video.)  At any rate, if we are flying in this manner, attempting to control heading with rudder, then too much bank could indeed produce some slip toward the GOOD engine, and too little bank would produce some slip toward the bad engine, both as indicated by a yaw string on the nose (rather than by the slip-skid ball-- though they will both basically agree whenever we are talking about huge deflections.) And when you lose an engine, initially one your first concerns probably is to apply rudder as needed to minimize yaw rate, so you might end up applying the controls in just this way. But fundamentally, the bank angle is not causing or preventing sideslip. Rather, the rudder is -- along with the yaw torque from the one working engine. In the long run, the bank angle is controlling turn rate, not sideslip.
IF airspeed is sufficient to give sufficient rudder authority to maintain the correct position of the slip-ball-- displaced about half a ball-width toward the good engine, then there ought not be any problem with turns in either direction.
On the other hand if you are fighting for basic control over the aircraft and you are having trouble preventing the aircraft from yawing and rolling toward the bad engine even with a lot of rudder applied-- which likely means the ball is still displaced rather far toward the good engine-- then the last thing you would want to do is bank toward the bad engine.  The additional turning tendency would exacerbate the difference in airspeed between the two wingtips and cause the aircraft to tend to roll toward the bad engine. Banking toward the good engine will have the opposite effect and help you prevent the aircraft from rolling toward the bad engine.

Disclaimer-- I'm speaking purely from theory here.  I don't fly twin-engine aircraft.

future edit-- "initially one OF your first concerns"....  also " And fundamentally the rudder, not the bank anlge,"  (angle).  Change "contained" to "contains"

Also, I wonder why the video shows Vmca being higher in the 0-slip condition (4 degrees bank) than at 5 degrees bank?

After sentence "The video is interesting but I think it contained some fundamental errors in theory if not result." say "The author incorrectly suggests that bank angle drives sideslip."   After sentence " At any rate, if we are flying in this manner, attempting to control heading with rudder" say "or in any case where the heading is constrained to be constant, then we DO end up with a correlation between bank angle and slip angle."

"fundamentally the bank angle, not the rudder, is what controls the position of the slip-skid ball"-- more editing for typos needed, coming soon.

After sentence "Rather, sideslip is a result of not being pointed the same direction you are actually going.", add another sentence noting that sideslip generates sideforce as the air strikes the side of the aircraft, and often we imagine that there is a direct correlation between sideforce and sideslip, but this isn't exactly true because the deflected rudder also generates some sideforce.

"The purpose of the banking toward the good engine is to stop the turn that would otherwise result (due to the rudder sideforce)"-- clarify that turn direction would be AWAY from deflected rudder, not towards it.  We aren't talking about a turn caused by fuselage sideforce but rather by the sideforce from the rudder itself.

This is correct, but there may still be some difference between the sides for two reasons: 1. the rudder position for coordinated turn is slightly different than in straight flight (though in many aircraft it is actually slightly out of the turn) and 2. the extra rudder needed to compensate for the adverse yaw of the ailerons when starting and ending the turn.

"And fundamentally the rudder, not the bank anlge, is the control what controls the position of the slip-skid ball." -- spelling error

Twin engines aircraft are designed to be relatively manœuvrable after V1 at takeoff whether they loose an engine or not. This is possible because the engines are not much apart from the X axis.
On modern aircraft such as the B 777 the thrust asymmetry is automatically compensated with the rudder. Once compensation is in place left turn and right turn, irrespective of the failure side, are symmetrical provided the aircraft speed is above a minima we will explain below.
Considering the worst condition, we loose the engines at take off, the aircraft is designed to be able to keep a minimum rate of climb with a speed not less than V2+10. Further when the airplane flies with an engine inoperative, there are redundancies in the design of the rudder, ailerons, elevators, and flap settings, which allow for the pilot to still control and fly the airplane, but to be able to control the airplane symmetrically the pilot must get the aircraft to a critical, minimal, controllable speed that the control surfaces can generate enough forces and moments to control the airplane, this speed is called VMCA (on ground we refer to VMCG).
Sure above these speeds we have full maneuverability, but we must understand how important they are when mapping out a flight plan, to plan for the unfortunate scenario where an engine is inoperative. Starting on the ground, if an airplane is on a runway and an engine gives out early, the pilot may be able to stop the airplane in time before the end of the runway, however if this is not the case then the pilot must take-off to avoid crashing the airplane at the end of the runway. This window of decision making is shortened if the airplane is on a short runway. If the pilot determines that they must take-off, then the calculations for the VMCG will blend into the calculations for the VMCA. It is extremely important for a pilot to know the bridge between these two speeds. If these speeds are relatively close to one another, the flight plan will merge from the VMCG to the VMCA. On the other hand if there is a major gap between these speeds then the flight plan should take this into account and adjust for it accordingly. Therefore there is a need to know these speeds and especially for the ability to calculate these speeds prior to the event of an engine failure. The flight plan becomes even more complicated if when there are geographical limitations surrounding the specific airport. These limitations include no-fly zones or mountains. Being able to calculate the VMCA and subsequently turn speeds will allow for a flight plan that will not crash the airplane into the surrounding topology.
For more details about VMCG and VMCA calculations please refer to :
https://repository.asu.edu/attachments/176507/content/Hadder_asu_0010N_16518.pdf

VMCA is a loss of control speed. I find it talked about here as if it has something to do with stall speed. This is not correct. Turning towards the dead engine is not a death sentence. Turning towards the dead engine does not cause the airplane to spin. The loss of control is rudder effectiveness. If you are turning with either engine inoperative and you are close to VMC I would ask,”Why are you even close to VMC?” If you are turning you should always maintain blue line or above. You should also, always be ready to reduce throttle on the good engine if you run out of rudder.
Also, in order for a spin to develop we have to fly below VMC, run out of rudder, not reduce bank, not reduce power. The spin actually occurs when the plane skids and blocks airflow to the wing with engine inoperative. That being said, do not try to lift your dead engine with ailerons when close to VMC. The down aileron causes more drag and skids the airplane causing it to block airflow to the wing with engine inoperative.

authors: Vladimir F Героям слава

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
Is a propeller a wing?
An aviation expert claimed to me that a propeller is a wing.
While I understand that propellers use similar principles to generate force, it muddied the definition of a rotary wing aircraft vs a fixed wing aircraft.  If the propeller of a fixed wing aircraft is considered a wing, what is the distinction between the two?  Is it how much surface area each type of wing works on?  Is it the direction of force?

maybe you should either rephrase the title or the question since the title states that you want to know whether a propeller is a wing or not, and the first sentence says that an aviation expert reminded you that it was. ;-)

It depends what you mean by 'is'. Is a tomato a fruit?

I don't think the edit that Jimy just made makes sense given the accepted answer. The question, as edited, asks "What's the difference between a rotary-wing aircraft and a fixed-wing aircraft?" The accepted answer is "No, a propeller is not a wing." In this case, instead of editing the title to match the body, the body should have been edited to match the title.

Calling a propeller a wing is not as accurate as calling a form of airfoil.

@TannerSwett agreed. I edited it back, and edited the body just slightly.

I think most people would say the answer is no. Consider the dictionary.com definition as it relates to Aeronautics:

9. Aeronautics .
  a. one of a pair of airfoils attached transversely to the fuselage of an aircraft and providing lift.
  b. both airfoils, taken collectively.

The wings are the big airfoils which are responsible for generating most of the vertical lift.
A colloquial test of this definition would be to grab a CFI and ask him/her to "point out the wings on this airplane to me." They won't point out the propeller. (Not a scientific experiment)
However, both wings and propellers are airfoils (and so are the other wing-like surfaces such as the vertical and horizontal stabilizers). You might get some disagreement about whether those other surfaces are wings, but I believe the answer is still no. There is nothing to be gained by calling them wings, and only leads to ambiguity. We already have a word which describes lifting surfaces in-general, and again, it's airfoil.

What about helicopters, which are commonly referred to as "rotary-wing aircraft"? Just because the airfoils are not attached to the fuselage doesn't mean they aren't wings.

@egid Well, I've never heard rotary-wings simply referred to as wings before, but it's possible. People call them rotors or rotorwings. Again, the word "wing" already has an understood meaning which we apply to airfoils intended for vertical lift. So my point was that I don't see any advantage in making the word "wing" ambiguous when we already have the word "airfoil" for that purpose. However, we are ultimately arguing over definitions which is perhaps too opinionated for the site anyway.

Is a propeller a wing? Maybe.  It depends on how pedantic you feel like being about your definitions.
A propeller is certainly an airfoil (usually several of them - each blade is an airfoil, and you can have one blade, two, three, four, or more attached to a hub).
A wing is also an airfoil.
Aerodynamically a wing and a propeller function the same way: Air moves over the surface of the airfoil(s), producing "lift". In the case of the wing the lift is mainly vertical and we call it "lift", while in the case of a propeller it's mainly horizontal and we call the resulting force "thrust" instead.

My two cents, ignoring all the dictionary pedantry? A propeller is an airfoil, but it is not a wing.
Why? Simple:
If I'm flying along and my propeller magically vanishes I'm now flying a really inefficient glider.
My day is ruined and when I catch the guy with the genie-in-a-lamp who wished my propeller away I'll probably beat them up, but I have a fair chance of putting the aircraft on the ground without killing myself or anyone else.
If I'm flying along and my right wing magically vanishes the genie-posessing miscreant is safe as I'm almost certainly going to die. All the lift from the remaining wing is going to try to flip the aircraft over, and I'm nowhere near skilled enough to keep control with a missing wing and land safely.

Regarding the "mud" this may throw on the definition of rotorcraft, bear in mind that rotorcraft are already pretty muddy (and I still personally believe that helicopters fly by black magic). A helicopter losing its entire rotor (all of the blades) is like an airplane that lost both wings (i.e. "A ballistic projectile."). One that loses a single blade is like an airplane that lost a propeller blade ("Probably going to tear itself apart from the unbalanced forces, becoming multiple ballistic projectiles"). A decidedly hybrid situation.

You ought to be flying a superb glider instead, anyway :D

An aviation expert reminded me that a propeller is a wing.

This is not false- a wing generates lift by creating a pressure difference, in the same way a propeller does. Wing typically refers to the structure lifting the main weight of the aircraft, while a propeller generates thrust, so from definition it's probably incorrect, from a theoretical standpoint it's the same principle.

While I understand that propellers use similar principles to generate
  force, it muddied the definition of a rotary wing aircraft vs a fixed
  wing aircraft.

A fixed wing aircraft will move at speed to generate sufficient lift to get airborne. A helicopter will be able to lift off vertically by spinning the blades quickly enough, which will have the same effect as moving forward.

If the propeller of a fixed wing aircraft is considered a wing, what is the distinction between the two? Is it how much surface area each type of wing works on? Is it the direction of force?

Propeller thrust is directed forwards. In level flight it contributes very little to lifting the plane up- that's left to the wings to do.
Rotary wing aircraft's blades do really work as a propeller: By increasing the angle of attack on one side, you generate more thrust, and the helicopter flies in the direction you want it to, since there's a force vector in that direction.

(source: tiscali.co.uk)
Distinction between the two: Rotorcraft generate the thrust to lift off themselves. A propeller generates the thrust (and in turn speed) necessary to create lift over fixed surfaces.

Since no one else mentioned this, I thought I would. Wilbur Wright, of the Wright brothers, said that a propeller was nothing more than a twisted wing.
If you accept his analogy, then the twisted wings that compose a propeller are clearly specialized wings, but they do generate a differential in air pressure above/in front of and below/behind as the surface moves through the air. That is what a wing does.

When one thinks with respect to plane, things are a lot less "muddy". Forget about definitions and rote and focus on what the function is.
First, while airborne, the only thing with respect to ground is gravity.  Everything else is dependent on orientation of the aircraft.
This is not muddy, it is actually a crucial step in becoming a better pilot.  So, starting with straight and level flight, it is obvious what is the wing (lift) and what is the propeller (thrust).
Now pitch up, add power and climb.  Yes, the propeller is now helping you climb as well as maintaining airspeed.  Is it now called a wing?  No, it is still out in front of the plane, so, with respect to plane, it is still the propeller!
The key is to draw the thrust vector, then break it down to vertical and horizontal components.  The propeller is helping lift the plane.
Now rotary wing aircraft.  All lift is provided by spinning the rotor, and forward motion too!  So it is both wing and propeller.  Birds have learned this trick as well!
So do not worry about muddy, take what you need and fly.

After doing a little more research, I have come to the conclusion that the answer is probably no. Since wings produce lift, I would argue that a propeller is not a wing since it does not produce lift, but thrust.
Since thrust is pretty much always perpendicular to lift, I can't see how the propeller would ever actually produce lift.

A propeller does generate lift. A propeller can even stall depending on its angle of attack just like any airfoil. Thrust is simply a direction of the force, not the cause of it. In the case of a propeller-driven aircraft, the thrust comes from the forward lift generated by the propeller. In the case of a jet or rocket engine, thrust would come from expelling hot matter at a high velocity.

@BretCopeland eh, I beg to differ. Why do fighter pilots talk about their lift vector, which is usually perpendicular to the wing?

In a typical airplane the propellers are perpendicular to the normal wings, so the "lift" direction of that propeller blade is aimed towards the front of the plane, perpendicular to the "lift" direction of the fixed wing.

@flyingfisch You are using all the wrong analogies.  Consider a propeller driven aircraft climbing vertically.  Is the lift generated by the wings now opposing the weight?  Where is the "lift vector"?

Think about the direction of the local relative wind experienced by the propellor blade.  Lift acts perpendicular to relative wind, and thrust and drag act parall to relative wind.


text:
Can an aircraft re-pressurize at high altitude?
When parachute jumps are performed from 32000 feet (or between 28000 - 30000 feet), once the jumpers are let out from the aft (cargo area), does the aircraft need to change altitude (e.g. descent)? Can the crew not pressurise the aircraft by simply closing the door?
In particular, I am talking about wide body aircraft with cargo deployment facility.

Pressurization is controlled by two processes: air in and air out.  Air is constantly being let out of the cabin through (at least) 2 outflow valves, typically located at the aft limit of the pressure vessel.  Air is let into the cabin through the air cycle machines (a.k.a the "packs") which are provided with very hot and high pressure air from the compressor stage of the engines and eventually output into the cabin through the air conditioning vents.
During normal cruise flight, the mass flow rate of air into the cabin is constant (because the flow rate through the engine compressor is constant), thus pressurization is maintained by actuating the outflow valves.  Open them up a little more to raise the cabin altitude, close them up a little more to descend the cabin altitude.  Note that while maintaining a constant cabin altitude the outflow vales are partially open -- the incoming air is more than adequate to pressurize the airplane.
When a main cabin door or something bigger is opened, the airplane will no longer maintain pressurization and everyone must don oxygen masks to avoid unconsciousness.  With a planned cabin dump, masks will be donned before the cabin is evacuated, which will happen before any doors are opened.  As noted by others, the pilot oxygen is fed from cylinders of pure oxygen and will last a long time.  Passenger emergency oxygen is from chemical oxygen generators and lasts 12-15 minutes.  I'm not sure what type of oxygen masks the HALO jumpers would wear, but presumably they have portable oxygen for the jump not related to the airplane oxygen facilities.
When all of the jumpers are away the doors are closed and once again the airplane is capable of pressurization.  The outflow valves will be commanded closed and the cabin altitude will start descending.  Once the cabin altitude is back down to normal levels, the crew will remove and stow their oxygen masks.
There is no need to descend to accomplish this because the air provided by the engines is much higher pressure than even sea level air.  Re-pressurization is accomplished by closing up the airplane and letting air accumulate in the cabin, thus raising the pressure.  Once the target pressure is realized (~8000 ft), then the outflow valves partially open to stop descending the cabin and to maintain the target pressure.

@caseyso what you are saying is that the pack flow control valves (aka FCVs) go to the normal opening position to suck in air from Engine LP stage and pressurise the aircraft. That makes sense now...thanks!

The only available source I found through searching the web is from a military watches forum, where a similar question has been asked and answered. The forum thread also references parachute jumping from high altitude, referred to as High-Altitude-Low-Opening (HALO) jumping.
Pressurization of an aircraft is accomplished through using bleed air from the compressor stages of the engines. The bleed air is then run through heat exchangers to match the temperature of the cabin and through  valves/regulators to achieve the desired pressurization of the cabin. Essentially this means that the aircraft can re-pressurize without a descent, by closing all doors and using the bleed air for pressurization. Since air density at high altitudes is very low, oxygen needs to be supplied from on-board tanks during the drop to counter hypoxia, which is why the crew needs to don their oxygen masks.


text:
Does sex occur in aircraft cockpits, and is this safe?
I've always heard euphemisms about pilots having sex with flight attendants or passengers while flying, but I'm wondering, does this ever happen on commercial flights or in general aviation?
Have there been incidents of sex in the cockpit when the participants got caught or their actions lead to something more disastrous (like a crash) wherein the truth about their actions was clearly exposed?

My guess is that this is one of many things that have changed in the passing years. I can assure you, though, that in the decade of the 1990s it did occasionally occur in airline cockpits, and before that in general aviation as well.
In particular in the days of the 3-man cockpit, the f.e. seat in both the 727 and the 747 had approximately 270 degrees of rotation, which allowed for excellent positioning.

Related meta discussion

pro tip: make sure the intercom is not on ;-)

@Terry: Tell us more! :P

As jwenting said, it's unlikely to happen for many reasons, and if it does, the participants are even less likely to admit it since doing so could get them in trouble both professionally, and with a government regulatory agency for endangering safety. I seem to remember the FAA taking action against a pilot who posted photographs of himself flying with either naked or bikini clad women at his side, but I can't seem to find a link right now.
There is one NTSB report which is somewhat famous in the aviation community for describing a general aviation crash which was likely caused by sexual activity. However, the summary is very delicately worded, to say the least:

The private pilot and a pilot rated passenger were going to practice simulated instrument flight. Witnesses observed the airplane's right wing fail in a dive and crash. Examination of the wreckage and bodies revealed that both occupants were partially clothed and the front right seat was in the full aft reclining position. Neither body showed evidence of seatbelts or shoulder harnesses being worn. Examination of the individuals' clothing revealed no evidence of ripping or distress to the zippers and belts.

ah, the beauty of bureaucratese.

The "probable cause" section is even more delicately worded: "probable cause(s) of this accident as follows: the pilot in command's improper inflight decision to divert her attention to other activities not related to the conduct of the flight"

@user568458 Sounds like an F18 'diverting' to a Boeing 747

Does it happen? Unlikely. The cockpit is a rather cramped environment with lots of sharp edges, knobs and switches sticking out, wouldn't be a lot of space for sexual encounters...
Also, crews are usually rather busy. Flight crew during the phases before and after cruise, cabin crew during cruise.

I'd not be surprised if there's the occasional romantic encounter in the crew rest areas of large aircraft on intercontinental flights but I'm pretty sure those involved will keep it quiet as it's no doubt a violation of company policy and could get those involved fired if they brag about it.
Far better to wait until you're on the ground in a crew hotel...

And even then, the promiscuity of airline staff is almost certainly way less than rumour would have it. These are not adolescent college kids on spring break, they're professionals on a tiring job where they can't drink and need regulation rest hours to be ready and fresh for the return trip the next day.

regarding your last paragraph it greatly depends on which airline you are talking about. Also plenty of overnights have adequate time for legal drinking.

Yes, casey is right. IIRC, the FAA rule is 8 hours "bottle to throttle," though it's my understanding that many (or most) airlines require 12. Additionally, in regards to the last paragraph, it actually used to be the case that almost all FAs were young, attractive, single females. It was actually a job requirement back before anti-discrimination regulations and public opinion changed that several decades ago. It's actually still the case in many parts of the world, especially Asia. Not so much in the West, though.

@reirab I agree about the stereotypical FA of the past and that's partially what prompted the question.

British Airways (or its predecessor) had an upper age limit and also a requirement that the FA be unmarried. Obviously pre-Sex Discrimination Act.

I am a pilot/mechanic and do not know of any recent 'activity'. But as recently as 2003 I was riding in the jump seat of a cargo 727. The FO came back from the terminal a little pissed and said they missed an 'opportunity' because I was in the jump seat. Later the crew told me they got sex from occasional passengers riding in the jump seat. I was surprised to learn that quit a few women hang out in airports and try to bum a ride from cargo haulers. I didn't ask for details, but I assume they took turns "checking the cargo". I was told the same thing by a pilot flying twin commuters.


text:
Would deploying the Space Shuttle's landing gear early have improved safety?
Due to the space shuttle orbiter’s high weight (potentially up to 110 tonnes [121 short tons] in certain abort scenarios, although nominally around 85 tonnes [94 short tons]) and abysmal subsonic aerodynamics, it landed at very high speeds (nominally 195 to 205 KIAS1, corresponding to as much as 215 KGS with a ten-knot tailwind allowance2).  As a result, a gear-up landing would have posed a considerable risk of voiding the warranties on the vehicle’s occupants:

NOTE
Bailout is preferred over a gear-up landing attempt.  [Space shuttle FCOM, page 6.9-2 (page 900 of the PDF of the manual); bolding in original.]

Despite the danger posed by a gear-up landing, the procedures for a normal shuttle landing did not call for extending the landing gear until on short final, approximately 300 feet AGL and a mere 20 or so seconds before ground impact; this would leave the crew with no good options in the event of a landing-gear-extension failure, forcing them to attempt a gear-up landing which would most likely destroy the orbiter and result in serious or fatal injuries to at least some of its crew (like we saw when we were trying to ditch the orbiter in the sea).
The safe deployment envelope for the shuttle’s landing gear opened much earlier than this; the gear were rated for safe deployment at up to 312 KIAS, and the shuttle, during a nominal approach, was already below this airspeed by the time it descended through 15 kft AMSL,3 and did not exceed it at any point thereafter.  If the gear were commanded down at 15 kft instead of 300 feet, this would leave time, in the event of a deployment failure, to turn towards a sparsely-populated area, pull out to 185-195 KIAS (the recommended bailout airspeed), engage the autopilot, and (for at least some of the crew) abandon ship (rather than pushing over into the normal 300-KIAS dive down the outer MLS glideslope in preparation for landing).
Deploying the gear at 15 kft, rather than when 300 feet above the rabbit, would likely have required the outer glideslope to be steepened slightly to allow the orbiter to maintain the 300-knot target speed with the added drag of deployed landing gear,4 but this would have been an easy and simple adjustment for the MLS providing the glideslopes (unlike with the more common ILS, where such an adjustment would require complicated reconfiguration of the glideslope antennae, possibly including physically moving the antenna array).
So why was the shuttle’s landing gear held in until it was far too late for any sort of meaningful remedial action in the event that the gear failed to deploy when commanded to do so?

(Not a dupe of this question; theirs asks whether, mine asks why.)

1: The shuttle FCOM uses KEAS (Knots Equivalent Airspeed) rather than KIAS (Knots Indicated Airspeed), but the two should normally be equal (assuming that one’s flight instrumentation is properly maintained and calibrated and that one’s pitot-static system is functioning properly).
2: The maximum allowable groundspeed at main gear touchdown was 225 knots, beyond which the orbiter’s tyres could not be guaranteed to remain intact.
3: It’s quite possible that the shuttle orbiter never reached or exceeded 312 KIAS at any point during a nominal reentry, approach, and landing (and not all that surprising if so, given that this was only 21 knots below the shuttle’s VMO of 333 KIAS, a margin easily wiped out by moderate horizontal windshear); however, I can’t confirm this above 15 kft, as this is the first entry in the FCOM’s nominal-reentry-approach-and-landing timeline for which an airspeed value (rather than a mach number) is listed.
4: The portions of entry and approach prior to MLS acquisition (S-turning, air-data incorporation, transonic flight, transition to manual control, and most of the nominal-energy procedure turn5) would not be affected (except for being moved slightly closer to the runway to compensate for the steeper outer glideslope), as these took place before the vehicle descended through 15 kft; the inner glideslope would likewise have been unaffected, as even a 300-foot gear deployment would still see the orbiter flying down all but the very beginning of the inner glideslope with gear locked down (unless, of course, it failed to deploy).  The minimum-energy procedure turn, performed closer to the runway than the nominal procedure turn and at a lower altitude, would likely have to be moved closer to the runway and flown at a higher descent rate to compensate for the higher drag from flying the procedure turn with gear deployed, but, again, ‘twould be but a simple tweak for the MLS.
5: Referred to by NASA as the “Heading Alignment Cone” (HAC), which is a fancy way of saying “procedure turn”.

15kft doesn't leave you enough time for a full bailout. Remember there is no ejection seat so it's quite slow for the crew to climb out one by one and there are quite a few of them. Even if you start at 30k you would be left with 10k when everyone is out.

@user3528438: Still much better than 300 feet, though.

I agree. But formalizing such a partial bailout procedure would likely lead to a series of PR trouble and further complicate the design.

@user3528438 Why is 10k ft not enough? You can skydive at 6k ft...

@Cloud It is enough, but you have to start the bailout at 30k to end up there.  If you start to bail out at 15k the shuttle will hit the ground while people are still trying to get out.

@quiet flyer: When people using units of measurement other than feet manage to build their own space shuttles, they will be entitled to use those units.

@jamesqf -- personally I'm kind of a fan of "octometers".  Pronounced like "thermometers".

@jamesqf good one. Remind me again, who was the first person to orbit earth in space? I keep forgetting.

@Jpe61: I thought we were discussing space shuttles here?   But if the Russians want to use some unit of measure other than feet in their information, they are perfectly free to do so.

Oh goodness. My nation is yet to produce a manned spacecraft, let alone a shuttle, what unit are we allowed to use? Fathoms?

It wasn't uncommon for the shuttle to exceed 312 KEAS during the preflare: https://youtu.be/KBTqtZIGV6U?t=1802. Not by much, but just thought I'd mention it since you seemed unaware.

Inflight Crew Escape System

At an altitude of about 9,150 meters (30,000 feet), astronauts would pull a handle that turns on the depressurization valve in the crew compartment bulkhead. This equalizes the cabin pressure and outside air before the side hatch is released.
At 7,620 meters (25,000 feet), the hatch is jettisoned and two
  telescoping sections of the aluminum and steel escape pole deploy
  through the hatch. Each crew member hooks a Kevlar® strap onto the
  pole, jumps out the hatch opening, slides down the 3.1-meter (10-foot)
  pole and goes into a freefall until the parachute opens to ease the
  journey to the ground. It takes approximately 90 seconds for a crew of
  eight to bail out of the Space Shuttle, and by that time, the vehicle
  is at 3,050 meters (10,000 feet) altitude.

So basically 15kft isn't high enough for everyone to bailout. Then you are faced with a few alternatives:

Still deploy the landing gear and evaluate at 15kft, and before the orbiter hits ground, hopefully but unlikely all of the crew get out and fewer have a chance to deploy parachute. It'll be extremely hard to explain this half-way solution to the American public.
Or, modify the design and procedure so that landing gears are deployed higher up so that they have sufficient time to fully bailout. This comes with all the problems with it. First of all, designing the landing gear to be deployed this high and fast, and the airplane that flies with it, wouldn't be easy. Also, the problem of inspecting the landing gear this high and fast is hard as well (it's pretty high, fast and faraway). Safe to say, the more you think about it, the more complicated it gets, while the project is already overly complicated.
Designing a landing gear that won't fail to deploy. This may sound impossible but since other things that may and do fail have lowered the bar considerably, making a landing gear that is relatively the least likely to fail isn't that hard at all.

For deployment of the landing gear, the uplock hook for each gear is
  activated by the flight crew initiating a gear-down command. The
  uplock hook is hydraulically unlocked by hydraulic system 1 pressure
  applied to release it from the roller on the strut to allow the gear,
  assisted by springs and hydraulic actuators, to rotate down and aft.
  Mechanical linkage released by each gear actuates the respective doors
  to the open position. The landing gear reach the full-down and
  extended position within 10 seconds and are locked in the down
  position by spring-loaded downlock bungees. If hydraulic system 1
  pressure is not available to release the uplock hook, a pyrotechnic
  initiator at each landing gear uplock hook automatically releases the
  uplock hook on each gear one second after the flight crew has
  commanded gear down.

If the orbiter gets to the point that the pyro+spring mechanism fails, it would have suffered sufficient structural damage that it wouldn't have made it anywhere near the runway(e.g. Columbia).

In (1) did you mean "evaluate", and it seems you a word.

+1 for using NASA-required units.

Also, we've gotten pretty good at landing gear.  Tens of thousands of flights per day for decades, and there've only been a relatively small number of landing gear failures in the history of aviation, most of which still managed to land safely (for the passengers at least, if not the plane.)

Designing reliable, redundand and robust  landing gears is not rocket science.

What good options would it add?
Remember that the Shuttle was a glider, and a spectacularly bad one at that.  You say "committed to landing" as if there was any point from re-entry onwards where the Shuttle was not fully committed to landing.
On a regular aircraft you can hit the throttle for a go-around.  Even on a regular glider you can stooge around in lift to buy time to think and perhaps time to figure out what's gone wrong.  You couldn't do that on the Space Shuttle though.  There's a reason it was nicknamed "The Flying Brick" - once you had started re-entry, you were on a one-way sled ride to the ground.  Whether the gear extended or not, there were no other options - you were going to "land" with or without gear!

They could bail out, given enough warning.

"Aahm Kennedy space center, STS-000 we have an unsafe gear indication, we're gonna go around and work our checklist." "STS-000 go around, maintain this frequency, advice when ready for another approach, Kennedy space center."


text:
What are the operational differences between an airplane equipped with a constant speed propeller and one with a fixed pitch propeller?
What makes a constant speed prop different from a fixed pitch prop, and what are the operational differences between airplanes with the two?

A constant speed propeller runs at a specific rpm by changing the blade pitch. When the blades are at a lower pitch (i.e., flatter angle), there is less air resistance, so the propeller puts less drag on the engine and runs faster. Additional pitch causes more drag and slower RPM. A governor (or something similar) will adjust the blade pitch to keep the propeller running at a particular rpm, even when more or less power is produced by the engine.
A constant speed prop is typically found on more powerful engines. Constant speed props are more efficient, but are more complex and heavier than fixed pitch props.
Some planes have a prop speed control for the pilot to adjust the propeller rpm, and some, such has the Cirrus SR22 and Pilatus PC12 have a single prop speed for flight.
The operation of a variable pitch prop depends on the plane. For example, in a Cirrus SR22 you don't even have a propeller pitch control. You operate it just like a fixed pitch prop. With a Pilatus PC12, the only prop pitch adjustments are when you feather the prop on engine shutdown or reverse the prop pitch for landing or ground operations. In a Beech Bonanza A36, you adjust the prop pitch for max RPM (minimum pitch) on takeoff, then add pitch for cruise flight, and max RPM for landing (in case of go-around).

See here for my own explanation of the workings of various constant-speed propeller systems.
The main operational difference is in power management. With a fixed pitch propeller, if you want more power for climb or speed, you add throttle. When you pitch up, the the RPM will slow due to less air moving through the propeller: suddenly instead of inertia helping you along, your engine is having to work to keep you going. When you pitch down, the RPM will increase due to more air moving through the prop. In this case you have to reduce throttle or you will overspeed the engine.
With a constant speed propeller, engine RPM is largely unaffected by the attitude and airspeed of the aircraft. The problem is that if you're flying along at cruise speed with your propeller in cruise configuration and decide to pitch up to climb, your propeller is not able to impart the full energy of the engine into the air. Your climb performance will be diminished or non-existant until you reset the prop to a low pitch. So the main thing to consider is that with a CS prop, maximum power is not always instantly available.
You can also damage the engine easier with a CS prop, in my opinion. With a fixed pitch prop if you go into a dive, your RPM will increase giving you visual and auditory clues that it's happening. With a CS prop, you can enter into a dive and possibly go all the way to Vne without the engine noticing a thing. The problem arises when you're going fast and decide you want to push the prop lever forward: your engine suddenly jumps hundreds or thousands of RPMs in an instant. This is extremely bad for it and that's why many aircraft manuals say not to increase to max RPM above a certain airspeed.
Finally, although it is more than made up for in efficiency, engine management is just more complicated with a CS prop. Say you're wanting to maintain a stabilized approach at 100kts. You need to find some combination of throttle and prop settings that gives you enough power to maintain a stable sinkrate, and either has enough drag to slow you down to 100kts, or has minimal drag, allowing you to keep your speed up.

I do not agree with the CS being complicated. I hate fixed pitch props, you have to constantly adjust the throttle to keep the RPM where you want it; on a CS you have predetermined power settings (you don't figure them out on the fly) for whatever you're doing, and you're free to concentrate on other things.

I don't like fixed pitch props either, but I'm not sure how you can argue that a system of two levers, flyweights, an oil pump, valves, pistons, gears, and springs is less complicated than moving one lever to add or reduce power.
You should not be constantly adjusting the RPM on a fixed pitch prop except when you change speed or attitude. Adjusting it all the time during cruise, climb, or descent will result in fluctuating speeds and climb/sink rates. But similarly if you set a CS prop to some setting and then change your attitude, your speed and climb/sink will change, forcing you to adjust.

Oh yeah, the system is definitely more complex. I just don't think it's more complicated to operate. Or perhaps it's more complicated, but once you're familiar with it, it's less of a burden on the pilot. For example, with the CS prop you usually have one setting (at least in small piston singles) for climb regardless of climbing airspeed and given that you usually transition from Vx to Vy to cruise climb on departure, that's kinda nice. With the fixed pitch prop you need to keep watch that you do not overspeed that prop when increasing airspeed.


text:
Which (if any) is the "most major" airport / field / strip on Antarctica?
Which airport (/field, /strip, /skiway) is the "biggest", "most supported" on Antarctica?
So,

has the most permanent staff (do any?)
has the most runway facilities such as say runway lights, markings, length, aircraft weight possible, surfaced (are any?), etc?
has the most or any fueling facilities?
the most or any ground support facilities? repair facilities?
is opened all or at least the most months of the year?

What's the state of the "best" airport (or analogue) in Antarctica?

You can find a full list of airports on the continent here, the majority are ice/snow runways with two gravel runways at Rothera Air Facility and TNM. Supported is a loose term down there, however Williams Field which services McMurdo Station is groomed and has fuel available. Phoenix Airfield which also serves McMurdo can accept wheeled landings and seems to be marked in some capacity. Marble Point (a helicopter landing site) is also operated by the US, has fuel available and is operable 24 hours a day in the summer and has weather reporting.
The full operations of the (US) bases can be found in this document which states

Williams Field is serviced by MLS, TACAN, and RNAV (GPS) approaches.
...
Phoenix Airfield is serviced by TACAN, MLS and RNAV approaches.

which is a solid set of approaches all things considered.
At least two fields have runway lighting

Airfield lighting systems are established at Phoenix and Williams
  Fields. The NSF Prime Contractor maintains airfield markings and
  lighting systems in accordance with AFMAN 32-1076

McMurdo even offers ATC!
All that considered Williams/Phoenix are your best bets but if you are trying to fly there on your own keep in mind:

All navigational and approach aids are intended strictly for use by
  USAP (United States Antarctic Program) approved aircraft only. The use of NAVAIDs by non-USAP aircraft
  are strictly at the pilot’s own risk.

All of the fields are "weather permitting" as are the flights so "open" all year is relative to weather conditions and other considerations.

Amazing answer!  (What's USAP ?)

United States Antarctic Program.  https://www.nsf.gov/geo/opp/antarct/usap.jsp

"intended strictly for use by USAP" and "strictly at the pilot’s own risk" -- Is this saying "please don't use these" or just "go ahead, but not our fault if something goes wrong"?

Indeed , that's' a critical question !  @TheGuywithTheHat

While this answer is absolutely AAA 1st class cabin, it would be great to hear from someone who flies there and has a local-knowledge answer!

I think you missed Teniente R. Marsh Airport: another airport with a gravel runway, and one of only two Antarctica airports with an IATA code: TNM.

@Will thanks for the heads up! I have added it.